Sudan's parliament has branded South Sudan's government an "enemy" and called for the swift recapture of a disputed oil-producing region, as rising border tensions pushed the former civil war foes closer to another full-blown conflict.

Sudan's parliament has branded South Sudan's government an "enemy" and called for the swift recapture of a disputed oil-producing region, as rising border tensions pushed the former civil war foes closer to another full-blown conflict.

South Sudan, which seceded from Sudan last July, seized the contested Heglig oilfield last Tuesday, prompting its northern neighbour to vow to recapture the area by "all means".

South Sudan claims Heglig as a part of the South and says it will not withdraw its troops unless the United Nations deploys a neutral force to monitor a ceasefire.

It accused Khartoum on Sunday of reducing the oil facility "to rubble" in an air strike, an accusation denied by Sudan.

"If any damage has occurred in Heglig it may have been on the part of the army of South Sudan," said Abdallah Ali Masar, Sudan's information minister.

But the UN has condemned South Sudan's occupation of the town and Ban Ki-moon, the UN secretary-general, repeated calls for South to withdraw troops and use "legal and diplomatic" measures to address the status of the town.

"He calls on both parties to end the fighting immediately and to respect international humanitarian law and the protection of civilians," a statement by Annan's spokesman said.

"He calls on the Government of Sudan to cease immediately all aerial bombardment of South Sudan territory. He also calls on the Government of South Sudan to withdraw immediately from Heglig and to use legal and diplomatic instruments to address its arguments on the status of Heglig."

UN camp targeted

Meanwhile, the United Nations Mission in South Sudan (UNMISS) on Monday confirmed that a UN peacekeepers' camp was among targets bombed by Sudanese warplanes.

Kouider Zerrouk, spokesman for the UNMISS, said there had been no casualties in Sunday's attack.

But a South Sudanese minister said that seven civilians had been killed and 14 others wounded in an attack on Mayom, while the region of Bentiu was also bombed.

Gideon Gatpan, the minister, said that two bombs had fallen in the UN camp, destroying a generator and a radio.